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Advice Needed(6 posts)

Advice NeededJames_M
Apr 2, 2003 5:20 PM
I have an 86 Trek road bike frame and misc. parts that I wanted to turn into a singlespeed using parts I have but I have a few issues. Can I use a fork off a bike with 27" wheels (since I have one) with a 700C wheel (don't have the 27" wheels)? The wheel and tire clear the crown by about a 1/16th of an inch and the brakes will work fine. I also have a 1" MTB stem which I was able to mount on my old Ritchey road bars without to much extra effort. It seems to hold very well but is it a bad idea to use this type of setup? I was also suprised to find that my old wheels (with a 7 speed freehub) fit in the rear triangle without any problems, what should the spacing be for this frame considering it came with a 6 speed freewheel?
Without seeing it, sounds fine. I have a similar setup...Silverback
Apr 3, 2003 8:57 AM
My singlespeed is a Trek 620 from about that same period. It's lived several lives with all kinds of components, including one season as a flat-bar, mountain-stem commuter with Suntour XC thumbshifters and Campy 990 derailleurs.
Assuming the steerer length is right and the brakes line up, I don't see why you couldn't swap forks (that tire clearance is tight, though...). I used a Ritchey stem for awhile with no problems (got a tall Nitto and mustache bars now). I can't remember the 6-7 speed spacing (126mm, maybe?), but if it works, why not?
it's fineSteve_0
Apr 3, 2003 1:11 PM
I routinely switch 27" and 700C on my 27" bike. Some guys with too much calculator time and too little riding time will argue that the 'optimal' total geometry is compromised; but empirical evidence says otherwise (besides, the geometry affect is no different than keeping the 'proper' size wheels but a difft profile tire).

The only thing i'm uncertain about in your setup, is why you only have 1/16th inch clearance; 27" wheels are LARGER than 700c, so if youre putting a smaller wheel on a fork meant for a larger wheel, I would expect clearance to increase.

Triangle distance irrelevant between 6/7.
it's fineJames_M
Apr 3, 2003 6:36 PM
I was originally told it was a 700c fork when I bought it. I was thinking it may be a 27" because I was mistakenly thinking 27" wheels were smaller than 700C (don't know much about road bikes). Is there any way it could be designed for a 650C wheel or would the 700C not even fit on that type of fork (again don't know much about road bikes)? I only paid 10 bucks for it and I could take it back and get credit for it. The fork is a unicrown design (hope that is the correct terminology, looks like my Kona P2 cross fork but with no canty mounts and it has curved legs) and the chrome finish is flawless. The other thing I found weird was that the Shimano 600 brakes lined up perfectly when I mounted them on the fork with the wheel installed.
Apr 4, 2003 4:45 AM
thats quite possible; the bead-seat diameter for a 700c is 622mm; if i recall correctly, the bead seat for a 650 is around 570mm. If youre looking at a 1/16th clearance with standard-profile tires, your looking at a 650 or 26" fork. Could also be a very low-clearance track fork.

Like I said, switching between 27" and 700c is fine (dependign on tire profile, only about 1/2" difference between the two), but 1/16th is a littttle to close for my comfort. Personally, I'd seek out a true 700c fork, or better yet, a 27" fork. I'll Bet your LBS has one laying around from the dude who 'had' to get the latest wiz-bang carbon fiber upgrade. He'll Probably sell it to you for 5 bucks.
Apr 4, 2003 5:23 AM
Used steel forks are very easy to pick up on eBay for cheap prices, if you need another fork. Many cyclists "upgrading" their bikes with carbon forks dump their steel ones on eBay. I've seen some really nice steel forks sell for $15-25 and carbon forks in the $50-100 range. Other good places to search include the classifieds and